Softub water chem?

[PNWpip]

Hi all. I’ve been reading the boards for about a month now with my new softub 220. We use it about 1-3 times a week. My dealer has a very hands off approach to water chemistry. (Add a cap of dichlor after every use, keep ph in range, everything else will sort itself out). After reading the boards, you could understand I’m suspect of the dealers advice. Softub warranty prevents any shocking and they do not recommend using any MPS as the low ph causes issues with the tub liner.
We’re on the first fill still, started with dichlor and transitioned to using the frog@ease. Ph has required moderate effort to keep in range by adding here and decreasing there, but TA has been very difficult to keep up. It drops to 0 in 2 days. Stabilizer has been at zero since day 1, but the dealer said don’t worry about it. Is this normal? All the boards I’ve read talk about HOW to increase/decrease TA, but I’m not seeing anything saying how OFTEN people are adjusting for TA. If my TA is so volatile, I’m sure that’s affecting my PH. At this point I can’t imagine not testing daily because things get out of hand every other day. How do you all set up your ph/TA so you can only check weekly?

[RDspaguy]

How are you testing?

Dichlor is almost half cya (cyanuric acid aka stabilizer) so if you are using dichlor you are adding stabilizer every time and it is accumulating in the water. How big is your "cap"? How big is your spa? It sounds like a recipe for extremely high chlorine and cya. High chlorine will bleach out the readings on all parameters, even chlorine, if not neutralized, so if you are using test strips you are not getting accurate readings, and even a test kit could be inaccurate.

Get a test kit if you don't have one, and read the sticky thread on dichlor/bleach method. 

@waterbear, can alkalinity be 0? Would that crash the ph?

[waterbear]

Alkalinity cannot be 0 for one simple reason. There is CO2 in the atmosphere and CO2 would be absorbed at the water surface to reach an equilibrium point. How are you testing the water? TA does not fluctuate quickly and the only way it can be dropped quickly is by the addition of a LOT of acid all at once. You never posted a set of test results so it's impossible to know what's going on in your tub. What is the initial TA reading, for example.

Please post a full set of test results, including Cyanuric acid (stabilizer) and how they were obtained (strips, drop based test kit, home meter or strip reader, or dealer system and whether it's a lab with liquid reagents, a reader reading a disc, or a reader reading test strips) and we can take it from there.